Apparatus and method for producing vibratory motions.



R. A. FESSENDEN. APPARATUS ANDMETHOD FOR PRODUCING VIBRATORY MOTION Lwmm I 8. APPLICATION FILED JAN-2. I913.

Patented Dec. 5, 1916.

* strains rrpn REGINAIJD A. JFJESSJENDEN, 0F BROOKLINE, MASSACHUSETTS, ASSIGINOR TO SUBMARINE SIGNAL COMPANY, 015 WATERVILLJE, MAINE, A CORPORATION OF MAINE.

v APPARATUS AND METHOD FOR PRODUCING VIBRATCRY MOTIONS.

' Specification of Letters Patent.

Patented Dec. 5, 191116.

' Application filed January 2, 1913. Serial'No. 739,630.

To all whom it may concern.

Be it known that I, REGINALD A. Fes- SENDEN, of Brookline, in the county of Norfolk and State of Massachusetts, a citizen of the United States, have invented a new and useful Improvement in Apparatus and Methods for Producing Vibratory Motions, of which the following is a specification.

My invention relates to means for securing a vibratory movement and more particularly to means for signaling by sound waves. I have shown certain'means, but I do not mean to confine myself to the means shown as other means will suggest them-' selves to those skilled in the art.

have shown in the drawings the preferred forms of securing my desired result, but I do not mean to limit myself to .the exact forms shown. My invention, however, will be understood from. the drawings, in Which- Figures 1 and 2 show diagrammatically two embodiments of my invention applied in each case to a diaphragm, and Fig. 3 shows diagrammatically a third embodiment of the said invention;

Referring to Fig. 1, 11 is a diaphragm closing one end of a horn 12 mounted in fixed position. 14,- 14 is a wire or preferably band of thin steel or a thin stifi metal tube. In the case of a bandit is best made of tough flexible steel such as that from which hand saws are made, but it may be made from a manganese steel though other material may be used such as horn fiber.

In using the word band or wire in this specification I mean to include any material or device capable of setting up vibrations in the manner herein described. 4 13 is a revolving wheel or device turning on its axis and preferably made of phosphor bronze or provided with a peripheral surface of phosphor bronze. The wire or band 14, 14 is wrapped around the wheel 13, one or both ends being connected with the diaphragm 11. In Fig.1, for example, the ends of the band 14, 17 which is passed through the diaphragm and secured by the adjustablenut 16.'

When the wheel 13 is rotated in such direction as to make 14 the tight end and 14 the loose end, the wheel 13 acts as a rotating snubbing block and pulls the diaphragm 11 to the right-until the diaphragm by lts the wire other spring member and the wheel 13.

14' are fastened to the pin motion to the right slackens the loose end 14 still further, to such an extent that the turns on the wheel 13 slip and the diaphragm returns to its normal position, after which the operation is repeated. This takes place automatically and at a frequency determined by the governing element, and forms a very efficient means of. producing reciprocating motion at high frequencies and with a minimum of inertia and power. It is of course immaterial in which direction the wheel 13 rotates when the strip 14, 14 is unincumbered with any attachment. By frequency determined by the governing element I mean a frequency determined by anything in the apparatus which may control or govern in any way the action of 14 including the diaphragm or The frequency may be determined by the natural period of the diaphragm 11 or of the band or wire 14, 14 which may be weighted. A. separate wire 18 stretched between two fixed points 20, 21., and attached to the end 14 by a clamp 19 may be used to determine the frequency of the end 14 while not materially aflecti'ng the frequency of the end 14, then by reversing the rotation of the wheel 13 so as to tighten the end 14' will tend to govern the natural frequency.

of the wire 14 when acted upon by the rotary member 13 because it will modify the natural vibrations of the wire 14.

Other means ofcontrolling the frequency of vibration are shown in Fig. 2 where in addition to the diaphragm 11, Wheel 13 and band 14, 14 a wheel 25 having projections is caused to rotate so that the projections will come in contact with the band. The rapid engagement of such projections with the band will of course change the tension inthe band 14 and so the frictional enga ement of the rotary member 13 with the band 14, thus disturbing the normal vibration of.

is. held. In

i the end 14, the coil 24 of the electro-magnet being connected to an alternating dynamo or energized by an interrupted current of high frequency, or the current from a telephone transmitter, caused to fluctuate by sounds, which are thereby reproduced bythe diaphragm 11. If a direct or uninterrupted current be used, the electro-magnet will serve as an attachment for one end of the strip, so that the end of the band or strip 14 will be held as in a vise or other means of stationary attachment, whereas if current from the alternating dynamo or an interrupted current is used there is again a modification of the natural frequency of the apparatus. By taking into consideration the frequency of the current controlling the electro-magnet 23 the natural period of the diaphragm 11 and, if used, the speed of rotation of the wheel 25, the tone or rate of vibration of the diaphragm 11 can be modified considerably. Any or all of these means may be tuned together so as to be in. resonance or two notes, for instance the octave, maybe produced in the two ends of the band.

It is to be noted that this method is sharply distinguished from the old method invented'by applicant (U. S. application, SerialNo. 400,134, filed October 31, 1907), in which a wheel covered with rosin is used,

and which depends upon the fact that the coeflicient of friction is greater for slowlymoving bodies than for fast, and which principle is utilized in bowing a violin. The

present method depends upon the fact that when the wire or band is not in contact merely, but is wrapped around the wheel, the friction increases as a logarithmic function of the angle, and a small pressure or tension applied at the point where the wire leaves the wheel makes a greatly multiplied pressure or tensionin the wire at the point where it commences to wind on the wheel. This fact is well known, as in snubbing a steamer to a dock, but its possibilities and advantages with a rotating snubbing block as a. means of producing reciprocating motion have neverxbefore been discovered or realized or applied when combined with an automatic frequency governing means.

The apparatus may be used for receiving sound waves, as for example byplacing a microphone 32 on" the diaphragm 11 as shown in Fig. 1, the microphone forming part of a telephonic receiving circuit.

The reciprocating'motion may be utilized not only to secure sound vibrations such as will be produced by the above apparatus but also for other purposes. For example, I have shown diagrammatically in Fig. 3 a saw 26 attached to the lever 11 which is pivoted at 31 on the support 27 In this case the end 14 if the band is attached to names? the other end of the lever 11' and when the wheel 13 is turned in. a direction to wind the end 14, the lower end of the lever 11 will be pulled to the right pulling the saw with it untilits armor pin 25 strikes the spring 29 attached to the support 27. The end 14 of the band is also attached to the spring 29 and when the pin 25 strikes the spring 29 it loosens the turns of the band 14, 14 on the wheel '13 so that the spring 28 retracts the saw. The motion is thus automatic and the stroke can be varied by varying the length of the pin 25.

Other applications of this invention will suggest themselves.

It is desirable that the wire or band and wheel run in a bath of oil or oil and graphite, though water or water and alkali may be used. Such a bath will reduce the harshness of tone which would result from an actual metal contact.

What I claim as my invention is 1. The method of producing vibratory motion of a spring-controlled member which consists in frictionally engaging said member to cause an increasing stress thereon until said stress becomes greater than and overcomes the frictional component when said member will Telease itself to be frictionally engaged again and automatically governing the periodicity of vibration of said member.

2. In a device of the kind described, the combination with a rotary member turning on its axis, of a wire wrapped around said rotary member, a spring member with which said wire is connected, and an automatic governing element to govern the frequency of vibration of said spring member.

3. In a device of the kind described, the combination with a rotary member turning on its axis, of a wire wrapped around said rotary member, a spring-controlled means to which one end of said wire is connected, and an automatically govering element to govern the frequency of vibration of said springmember.

4. In a device of the kind described, the combination with a rotary member turnin .on its axis, of a wire wrapped around sai rotary member, a vibratory'device mounted in fixed position and to which one end of said wire is connected, and means for automatically governing the periodicity of vibration of said vibratory member.

5. In a device of the kind described, the combination with a rotary member turning on its axis, of a wire wrapped around said rotary member, a vibratory device with which said wire is connected, and means engaging said wire whereby its frequency of vibration may be automatically governed.

6. In a device of the kind described, the combination with a rotary member turning on its am's, of a wire wrapped around said meme? m which said Wire is connected, and means whereby the frequency of vibration of said wire may be automatically governed.

7. As a means of producing vibratory motion, the combination with a member to be vibrated, of a rotating member turning on its axis, a vvire wrapped around said member and one end of which is connected with said member to be vibrated, and an automatic frequency-governing member with which the other end of said Wire 1s connected.

8. As a means of producing sound, the

combination with a rotating member turning on its axis, of a vibratory member mounted in fixed position and capable of producing sound, a Wire Wrapped around said rotating member, one end of said Wire being connected to said vibratory member, and an automatic frequency-governing member with which the other end of said Wire is connected.

REGINALD A. FESSENDEN. Witnesses:

HAROLD J. W. FAY, EDGAR S. Fos'rER. 

